Gramopholte-amplifieit



W. R. FREE.

GRAMOPHONE AMPLIFIER.

APPLICATION FILED AUG.28. 191m .1 318,201. Patented Oct. 7,1919. 2 SHEETS-SHEET I.

W. R. FREE.

GRAMOPHONE AMPLIFIER.

APPLICATION FILED AuG.28. 1918.

1, 3 1 8, 2O 1 Patented Oct. 7, 1919.

2 SHEETS-SHEET 2.

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section of a gramophone E STATE ric.

WILLIAM rwssrmr. FREE, or PIQUA, onto.

GRAMOPHONE-AMPLIFIEB.

To all whom it may-concern Be it known that I, WILLIAM RUSSELL FREE, a citizen of the United States, residing at Piqua, in the county of Miami and State of Ohio, have invented certain new and useful Improvements in Gramophone- Amplifiers, of which the following is a.

connection with a generator or dynamo.-

driven by the motor of the machine and having coupled in the circuit, a resistance element to regulate the 'tone as desired, while the sound produced is received by the transmitter and conveyed by the. receiver as and for the purposes specified.

With the above and other objects in view, as will appear as the description proceeds, the invention comprises the novel features of construction, combination of elements and arrangement of parts which will be more fully described inthe following specification and then finally embodied in the clauses of the claim appended hereto.

,Reference is had tothe accompanying drawings forming a part of this application, in which-.-.

Figure 1 1s a'perspectiv e view partly in improved tone and sound amplifier,

' Fig. 2 is an enlarged sectional view showing the amplifier device, Fig. 3 is a diagrammatic view showing the circuit. arrangement, also the connection be tween the generator or dynamo and themotor of the machine,

Fig. 4 is a plan view of the resistance switch, and e Fig. 5 is a sectional view of the top of the gramophone and switch applied thereto.

Referring to the drawings in detail,'the numeral 10 designates the cabinet of a graphophone or gramophone having the usual cover 11 designed to close over the table'12' adapted to be rotated by the usual motor contained;within a compartment or chamber Specification of Letters Patent.

equipped withmy Patented Oct; 7, 1919.

Application filed. August 28, 1918. Serial No. 251,788.

13 so as to revolve the disk record 14 therewith. The tone arm is designated at 15 havlngthe gramophone sound box 16 with a needle 17 cooperating with the record, said tone arm leading tothe sound box or horn 1 18 which issues from the cabinet, which latter may be of anypreferred type, adapted to contain records if desired, or.not.. The

. motor may be of any suitable type, and may be electrically driven or a. spring motor adapted to be wound by a crank19 so as to rotate the table 12 when the brake 20 is released, as it is thought will be understood.

order-to amplify the tone and sound issuing from the tone arm and the sound box or horn 18, interpose in the reduced portion 21 of the sound box or horn, a casing22 designed to "contain a transmitter 23 with a carbon grain sensitive microphone, the same being coupled to the reduced portion 21, by

the tubular connection at 24. A partition 25 1s provided in the casing 22 and the casing is thereby divided into a pair of chambers in the other of which is disposed a receiver 26, the receiver being of the loud talking type and electromagnetic, while the transmitter has a microphone of the sensitive type. The receiver has a connection with the sound box or horn 18 and the terminals 27 and 28 of the transmitter and receiver respectively are connected by a conductor 29 extending through the partition 25. The other terminals 30 and 31 of the transmitter andthe receiver respectively, are connected through the medium of conductors 32 and 33 withragenerator or dynamo 34 operatively connected to the motor 13 through the med-ium of a shaft'35 or other operative connections, bywhich the dynamo may be rotated at. the proper speed, by means of the '-motor which turns the table for revolving the disk record. Interposed in the circuit .is a switch rheostat 36, consisting-of a variable resistance-in the form of a plurality of contacts 37, one end of the generator beingconnectedto the movable contact member 38 of the switch rheostat by a conductor 39, while the conductor 32 is connected to one of the transmitter leads and to one of the contacts of the switch rheostat and a conductor 40 from'the conductor 33 leadsto theother extreme contact of the switch rheostat. 'The contact'38 is mounted on a pivot 41 designed to be passed through the top of the cabinet 10 and operated through the medium of a handle portion 42 provided with an index pointer43 coiperating with a circular scale plate 44, which latter indicates the degrees of resistance, which shall be such as to produce the proper tone and clarify the same according to the desires of the person operating the machine. It is of course understood 7 that the sound is received by the transmitter and conveyed through the circuit wires the particular type of transmitter andreceiver employed, the sound will be considerably amplified, thereby producing aclear tone as well as a lender tone.

From the foregoing description taken in connection with the accompanying drawings, it is thought that a clear and comprehensive understanding of the construction, operation and advantages ofmy invention may be had, and while I have shown and. described the device asembodying a specific structure, I desire that it be understood that such changes may be made in said structure as do not depart from the spirit and scope of the invention as claimed.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is: 1. The combination with a graphophone having a sound box and a motor for driving the record receiving table-for engagement by the sound box carried by the tone arm in the usual manner, a casing interposed in the tone arm, a transmitter therein having connection with the tone arm, a receiver having electrical connection with the transmitter and leading to the horn or sound box, a dynamo operatively connected with the motor of the machine, and connected in an electrical circuit with the transmitter and remitter having a carbon grain sensitive micro phone, a receiver disposed between the partition in the casing and the horn, said receiver having a loud talking electromagnetic microphone, a conductor connecting two tel-mi nals of the transmitter and receiver, a source of electrical energy having electrical connection with the receiver and with the transmittelyand an adj ustable resistanceelement in the connection between the source of electrical current and the receiver and transmitter.

3. The combination with a graphophonc, of a casing interposed between the tone arm and the horn thereof, a partition in said casing, a transmitter in said casing between the tone arm and the partition, said transmitter having a carbon grain sensitive microphone, a receiver disposed between the partition in the casing and the horn, said receiver having a loud talking electromagnetic microphone, a conductor connecting two terminals of the transmitter and receiver, a

source of electrical energy having electrical connection with the receiver and with the transmitter, and an adjustable resistance element in the connection between the source of electrical current and the receiver and transmitter for varying the current flowing through said transmitter and receiver, said resistance element including a series of contacts associated with a resistance coil, and a movable contact cooperating with said first mentioned contact, and an index plate under which said movable contact is operable to vary the degrees of resistance.

In testimony whereof, I affix my signature hereto.

WILLIAM RUSSELL FREE. 

